I did not set out to write about St Francis. But slowly and organically, over the course of three years and two holidays in Umbria, the idea grew. If any moment crystalised it, it was perhaps the trip I made with a friend to the hilltop shrine of La Verna, where Francis received the stigmata.

There I found myself transfixed less by the beautiful della Robbia sculptures, which I had mostly come to see, than by the hollowed-out rock, in a grotto dripping with ferns and water, which the saint had chosen for his bed.